Compressed air systems are used in a variety of industrial settings and manufacturing facilities. In the U.S., compressed air systems account for $1.5 billion per year in energy costs. In fact, it is estimated that compressed air systems account for 10% of all electricity used in U.S. manufacturing. In some industries, compressed air systems account for 30% or more of the total energy cost of a manufacturing facility. Many industries use compressed air systems as power sources for tools and equipment used for pressurizing, atomizing, agitating, and mixing applications.
The costs associated with a typical compressed air system are generally broken down as follows: equipment and installation costs account for about 12% of the lifetime cost of the system; maintenance and downtime account for about 12% of the lifetime cost of the system; and electricity (power) accounts for about 76% of the lifetime cost of the system. Thus, maximizing the efficiency of the system to provide more air using less energy will provide the greatest area for lifetime cost reduction for a compressed air system.
Recently, there have been many attempts to identify inefficiencies in compressed air systems and optimize those systems through intelligent control systems and/or specially designed equipment. Compressed air system optimization can result in a 20-50% savings in energy, and the costs associated with improvements and additional hardware and software are often paid back in 1-3 years or less.
A problem lies in the ability to accurately predict the efficiency of a compressed air system and identify the weak points. Before a facility will commit to spending money on new compressed air system components, operating software, or further analysis of the system, a payback period or return on investment must show that these changes are economically advantageous.
It is, therefore, desirable to provide a method for determining the efficiency of a compressed air system such that improvements to the system can be quantified and measured against a current efficiency and a maximum efficiency. This will better assist decision makers when evaluating compressed air system changes.